Ruins of a portion of the emperor Nero’s Golden House are found on the Esquiline, although the palace once occupied the Palatine and the Caelian hills as well. After the fire of 64 ce had destroyed so much of the city, Nero undertook to rebuild more than 200 acres (81 hectares) of it as a palace for himself: seawater and sulfur water were piped into its baths; flowers were sprinkled down through its fretted ivory ceilings; and the facade was covered in gold, from which the name Domus Aurea (Golden House) derived. The expropriation so enraged the citizens that his successors hastened to efface all trace of Nero’s incredible palace: the ornamental artificial lake was drained, and on its bed the Colosseum was erected for free entertainment; Trajan built magnificent baths—also with free admission—atop the domestic wing of the Golden House; and Domitian converted the portico on the edge of the Forum into Rome’s smartest shopping street. The obliterators were aided by the fire of 104 ce. Less than 70 years after the Golden House had been started, nothing was left of it but a huge gilded statue of Nero, later destroyed by one of the early popes. The removal of the Golden House was so complete that later Romans could not remember where it had stood. When the domestic wing of the palace was discovered under the remains of Trajan’s Baths in the 15th century, the rooms painted in the Pompeiian style were thought at first to be decorated grottoes. Some years later, when the painter Raphael and his friends were let down on ropes to look, the style they imitated in decorating the Vatican loggias was called grottesche (see also grotesque).

Trajan’s Baths served as models for the Baths of Caracalla and Diocletian, which in turn served as a pattern for the basilica built by Maxentius. The bath building that housed the hot, warm, cold, and exercise rooms and the swimming pool was a huge rectangular concrete structure lined with marble. It was surrounded by a garden enclosed in an outer rectangle of libraries, lecture halls, art galleries, and other facilities of a big community centre.

Located between the Esquiline and the Palatine, the Basilica of Maxentius (also named after Constantine I, who completed it after dispatching Maxentius) was started about 311. This massive hall of justice and commerce was covered by three groin vaults with three deeply coffered tunnel-vaulted bays on either side. It was probably ruined by the earthquake of 847 and was also mined for its materials. One of the great Corinthian columns stands obelisk-like before the Santa Maria Maggiore church on the Esquiline. The head of a colossal statue of Constantine that once stood in the basilica now reposes in the courtyard of the Palazzo dei Conservatori.

The Viminal and Quirinal

Like much of the Esquiline, the adjacent Viminal and Quirinal hills lie in the heart of modern Rome. Heavily built upon and sclerotic with traffic, the former seems almost flattened under the Ministry of the Interior. The ancient Baths of Diocletian (c. 298–306) are northeast of the Viminal. Some idea of their size (130,000 square yards [110,000 square metres] for the main bath block) can be gained from the fact that the church of San Bernardo was built into one of the chambers some 500 feet (150 metres) west of the central hall of the frigidarium (cold room), into which Michelangelo built the cloister church of Santa Maria degli Angeli in 1561. A portion of the Museo Nazionale Romano (National Museum of Rome) is housed in the baths complex. This matchless collection of antiquities includes wall paintings from villas, mosaics, sarcophagi, and sculptures.

The Quirinal, pierced by a modern traffic tunnel, has been a distinguished address since Pomponius Atticus, recipient of the statesman Cicero’s letters, was a resident in the 1st century bce. Starting with the Crescentii, who planted the family fortress there in the Middle Ages, powerful Roman families built their homes in this location. The Palazzo Colonna, at the foot of the hill near the Via del Corso, is an art gallery open to the public; its gardens, climbing the slope to the Piazza Quirinale, contain remnants of Caracalla’s Temple of Serapis. The piazza has been graced since antiquity with two large statues of men with rearing horses, The Horse Tamers, or Castor and Pollux. Closed on three sides by palaces, the piazza opens on the fourth to a splendid view over the Tiber.

The Palazzo del Quirinale (Quirinal Palace), built by Pope Gregory XIII in 1574 as a summer palace away from the heat and malaria of the Vatican, was enlarged and embellished over the next 200 years by a succession of noted architects. The palace, with many extensions and wings, is huge, and its garden is five times as big as the building. From 1550 to 1870, the Quirinal rather than the Vatican was the official papal residence. In 1870 it became the royal palace of the new Kingdom of Italy and in 1948 the presidential palace. Both monarchs and presidents, however, have preferred to inhabit the homier palazzetto (“little palace”) at the far end.

The handsome buildings opposite are the stables (1730–40), built on the site of the Crescentii 10th-century stronghold. This zone is now used as a site for major art exhibitions. The Palazzo della Consulta (1734), erected for part of the papal administration, became the home of the Italian Constitutional Court in the 1950s. The Palazzo Pallavicini-Rospigliosi, built by a cardinal of the Borghese family in 1603, is still a private house.

The Palazzo Barberini farther up the Quirinal, constructed during 1629–33 on the site of the old Palazzo Sforza, was occupied by the Barberini family until 1949. Part of the collection of the Galleria Nazionale d’Arte Antica (National Gallery of Ancient Art) is housed here, the rest across the river in the Palazzo Corsini in the Trastevere rione (district). The pictures, most of them works by celebrated masters, were contributed by distinguished families, including the Barberini. Architecturally, the Palazzo Barberini is important because it marks a departure from the heavy-set four-square town houses of the early and High Renaissance. In the Rome region, only country villas had been built on so open a plan, with two wings coming forward from an open, arcaded facade. Further, it pioneered the Baroque style in domestic architecture.

Carlo Maderno, who put the facade on St. Peter’s Basilica, made the plans for the Palazzo Barberini, which were carried out after his death by Gian Lorenzo Bernini, assisted by Francesco Borromini. Each of these two rivals has a church just around the corner. After 20 years of apprenticeship, Borromini was given his first chance to do his own building. It was a church at an impossibly tiny site at the crossroads of Quattro Fontane (“Four Fountains,” one of which is built into a niche in the church wall), but his creation, San Carlo alle Quattro Fontane, was a triumph. To his revolutionary solutions for site problems, for which he employed a brilliant variation on the oval, Borromini added a facade in 1667, the year he died, which responded to the waves of motion generated by the spatially complex interior. His work created a sensation, and his ideas were seized upon by Baroque artists, especially from other countries. Bernini’s Sant’Andrea al Quirinale is also small, but it took 12 years to build (1658–70), late in his career. An oval building with the naves sculpted into the outer wall, it enlarges on concepts advanced by Michelangelo. Bernini’s use of coloured marbles and shrewd lighting effects gives the small structure extra dimension. Nearby is the Teatro dell’Opera (Opera House), built in 1880 by Achille Sfondrini. It was acquired by the state in 1926 and is Rome’s most important lyric theatre.

Other hills

Behind the Piazza del Popolo is the Pincio (Pincian Hill). During the Roman Empire the Pincio was covered with villas and gardens, but it was made into a public park only in the 19th century. Toward sunset many Romans arrive to stroll along the Pincio promenade.

On the hill is the Villa Borghese, which the Italian government purchased, along with its contents and grounds, at the turn of the 20th century. The grounds are now an extensive park containing numerous museums, academies, monuments, natural features, and other attractions. In the villa itself, the Galleria Borghese’s collection features several Caravaggios, Titian’s Sacred and Profane Love, and Antonio Canova’s Neoclassical nude statue of Pauline Bonaparte, for a time a Borghese princess, as Venus Victrix.

The 1544 Villa Medici was bought by Napoleon in 1801 to house the Accademia di Francia (French Academy), which is still in occupation. This academy, founded in 1666, is the oldest of many national academies established from the 17th to the 19th century to give architects, artists, writers, and musicians the opportunity to study the vast textbook that is the city itself and to use its museums and libraries. The Villa Giulia was a typical mid-16th-century Roman suburban villa, conceived not as a dwelling but as a place for repose and entertainment during the afternoon and early evening. It houses the Museo Nazionale di Villa Giulia (Villa Giulia National Museum), which has a collection of Etruscan art and artifacts of singular beauty and historical value. Other attractions of the Borghese grounds include the Galleria Nazionale d’Arte Moderna (National Gallery of Modern Art), founded in 1883, with an important collection of 19th- and 20th-century Italian art, and the Bioparco–Giardino Zoologico (Biopark–Zoological Garden), established in 1911.

Across the river, behind the river plain of Trastevere, is the Gianicolo (Janiculum Hill). The Janiculum crest was made into a park in 1870 to honour Giuseppe Garibaldi for his heroic but unsuccessful defense of the short-lived Roman Republic of 1849.